The Ansei Nankai Quake (安政南海地震, Ansei Nankai Jishin) was an 8.4 magnitude earthquake which struck on December 24, 1854. Over 10,000 people from the Tōkai region down to Kyushu were killed.[1]

The Ansei Edo Quake (安政江戸地震, Ansei Edo Jishin) was a 6.9 magnitude earthquake which struck Edo (modern-day Tokyo) on November 11, 1855. One hundred and twenty earthquakes and tremors in total were felt in Edo in 1854-55. The great earthquake struck after 10 o'clock in the evening; roughly 30 aftershocks continued until dawn. The epicenter was near the mouth of the Arakawa River. Records from the time indicate 6,641 deaths inside the city, and 2,759 injuries; much of the city was destroyed by fire, leading many people to stay in rural inns. Aftershocks continued for twenty days.[1] This quake was a particularly destructive deep thrust quake caused by a giant slab of rock stuck between the Philippine Sea Plate and the Pacific Plate.

The earthquake was blamed on a giant catfish (Namazu) thrashing about. Ukiyo-e prints depicting namazu became very popular around this time.

Other notable quakes to strike in the Ansei period include one in the Iga area, one which registered 7.4 on the Richter scale and struck Kyushu and Shikoku .